STAT3 and neoplasm: To confirm the fundamental role of STAT3 in regulating the glycolytic switch of STAT3-dependent tumour cells in vivo, glucose uptake by xenografted MDA-MB468 tumours was measured in the presence or absence of the S3I treatment by means of PET analysis using the radioactive glucose-analogue 18F-FDG (PET-FDG, Figure 7D).